For all Business Add-Ins defined in the Enterprise Core that are to be implemented only by Enterprise Extensions, set the SAP Internal checkbox field.
You do this for the following reason:
At the technical level, Extensions are represented by structure packages, which sit on top of the SAP Enterprise Core independently of each other, and which do not define dependencies to one another. Each extension is delivered as a single add-on, which is always installed when the SAP Enterprise Core is installed or upgraded. A switch is needed, since there is no way of interrupting the flow of the process extensions of core processes by means of an extension.
You create a switch by defining an application in the transaction FIBF, where the application code is identical to the code assigned to a structure package.
These switches can be activated or deactivated by the customer in transaction FIBF. (However, we do not advise users to deactivate switches, since inconsistencies may occur if a structure package has been active in the customer’s system for a long time.)
If you set the SAP Internal checkbox for a Business Add-In, it is automatically deactivated unless the switch is set. (That is, Business Add-In implementations that belong to the structure package are not executed.)
Using the function module GET_R3_EXTENSION_SWITCH, you can determine whether a switch is activated or deactivated.